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Title: On-line tests of organic additives for the inhibition of the precipitation of silica from hypersaline geothermal brine

Technical Report ·
DOI:https://doi.org/10.2172/6444210· OSTI ID:6444210

A number of compounds have been screened as potential scale control agents by examining their effect on the precipitation of silica from Magmamax No. 1 brine. The substances were tested using the Lawrence Livermore Laboratory scale-control test system at the Niland, California, test site. Solutions of the test substances were injected into flowing brine at approx. 200/sup 0/C, the brine was flashed at 125/sup 0/C, and then the kinetics of solids and silica precipitation from effluent brine held at 90/sup 0/C were measured. Compounds tested include a variety of cellulose derivatives, ethylene oxide polymers, several polyethoxylated surfactants, and a phosphonate. The ethylene oxide moiety was confirmed as the source of activity in substances that inhibit the precipitation of silica at 90/sup 0/C, and the polyethylene glycols in the molecular weight range of approximately 10,000 to 100,000 are the most effective. A brief, in-plant scaling test with the most promising precipitation inhibitor showed that, although it significantly retarded scaling at 90/sup 0/C, there was no improvement at 125/sup 0/C or higher, and at 125/sup 0/C there may have been a slight increase in scaling rate.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
6444210
Report Number(s):
UCID-18091
Country of Publication:
United States
Language:
English